"""
请写出一段 Python 代码实现删除一个 list 里面的重复元素
list1 = [1,2,3,5,2,1,5,7,9]
"""
list = []
list1 = [1,2,3,5,2,1,5,7,9]
set1 = set(list1)
for char in set1:
    list.append(char)
print(list)
